Polycystic ovary syndrome (PCOS), also known as polycystic ovarian disease or Stein-Leventhal syndrome, affects an estimated 6–10% of women in the United States. PCOS is characterized by anovulation (irregular or absent menstrual periods) and hyperandrogenism (elevated serum testosterone and androstenedione). Additional etiological and clinical symptoms of this disease can include abnormal uterine bleeding, enlarged multifollicular ovaries, infertility, obesity, insulin resistance, hyperinsulinemia, hypertension, hyperlipidemia, type-2 diabetes mellitus, excess facial hair growth, hair loss and acne.
Insulin resistance and hyperinsulinemia are highly prevalent in patients with PCOS and are thought to underlie the pathophysiology of this disease (Udoff, L., et al., Curr. Opin. Obstret. Gynecol. 7:340–343 (1995); Barbieri, R. L., Am. J. Obstet. Gynecol. 183:1412–8 (2000); Kim, L. H. et al., Fertility and Sterility 73:1097–1098 (2000); Iuorno, M. J. et al., Obstet. Gynecol. Clin. North Am. 28:153–164 (2001); Zacur, H. Z., Obstet. Gynecol. Clin. North Am. 28:21–33 (2001)). Recent studies suggest that the hyperandrogenism associated with PCOS is caused by an increase in ovarian androgen production (e.g., testosterone and androstenedione) and a decrease in serum androgen-binding globulin concentration, due to hyperinsulinemia. Insulin has been shown to directly stimulate production of androgens by the ovary, at least in part by increasing the activity of P450c17α, an enzyme involved in the production of testosterone in the ovarian theca cells (Iuorno, M. J. et al., supra). At the level of the pituitary axis, hyperandrogenism suppresses follicle stimulating hormone (FSH) secretion, alters gonadotropin-releasing hormone (GnRH) release and increases lutenizing hormone (LH) secretion. These abnormalities, along with the local effects of androgens on the ovaries, lead to follicular involution, anovulation, and infertility. Similarly, oligomenorrhea and amenorrhea occur and are interspersed with heavy vaginal bleeding. Hyperinsulinemia may also lead to high blood pressure and increased clot formation and has been implicated in the development of cardiovascular disease, stroke and type-2 diabetes (Iuorno, M. J. et al., supra; Zacur, H. A., supra).
Traditionally, treatment of PCOS was directed primarily at correcting the underlying symptoms. For example, hirsutism and menstrual irregularities were treated with anti-androgenic drugs, including birth control pills, spironolactone, flutamide or finasteride. Infertility treatments have included weight loss diets, ovulation medications (e.g., clomiphene, follistim and Gonal-F), so-called “ovarian drilling” surgery, and in vitro fertilization. More recent treatments for PCOS are targeted towards lowering insulin levels. Insulin-sensitizing agents such as metformin, D-Chiro-inositol, diazoxide, and PPAR-gamma inhibitors (e.g., troglitazone (Rezulin), rosiglitazone (Avandia) and pioglitazone (Actos)), have been demonstrated to restore fertility and reverse the endocrine abnormalities associated with PCOS. Although metformin and PPAR-gamma inhibitors do not interfere with pregnancy, they are generally discontinued during pregnancy because of concern over their safety and effect(s) on the fetus. Moreover, women with PCOS who become pregnant experience spontaneous abortion during the first trimester at rates as high as 30% to 50% (Iuorno, M. J. et al., supra; Zacur, H. A., supra; Phipps, W. R., Obstet. Gynecol. Clin. North Am. 28:165–182 (2001). Thus, there is a need for new and better compositions and methods for treating PCOS.